ath79: add support for ALFA Network N2Q

ALFA Network N2Q is an outdoor N300 AP/CPE based on Qualcomm/Atheros
QCA9531 v2. This model is a successor of the old N2 which was based
on Atheros AR7240. FCC ID: 2AB8795311.

Specifications:

- Qualcomm/Atheros QCA9531 v2
- 650/400/200 MHz (CPU/DDR/AHB)
- 128 MB of RAM (DDR2)
- 16 MB of flash (SPI NOR)
- 2T2R 2.4 GHz Wi-Fi with ext. PA (Skyworks SE2623L) and LNA
- 2x 10/100 Mbps Ethernet with passive PoE input in one port (24 V)
- PoE pass through in second port (controlled by GPIO)
- support for optional 802.3af/at PoE module
- 1x mini PCIe slot (PCIe bus, extra 4.2 V for high power cards)
- 2x IPEX/U.FL connectors on PCB
- 1x USB 2.0 mini Type-B (power controlled by GPIO)
- 8x LED (7 of them are driven by GPIO)
- 1x button (reset)
- external h/w watchdog (EM6324QYSP5B, enabled by default)
- UART (4-pin, 2.54 mm pitch) header on PCB
- LEDs (2x 5-pin, 2.54 mm pitch) header on PCB

Flash instruction:

You can use sysupgrade image directly in vendor firmware which is based
on LEDE/OpenWrt. Alternatively, you can use web recovery mode in U-Boot:

1. Configure PC with static IP 192.168.1.2/24.
2. Connect PC with one of RJ45 ports, press the reset button, power up
   device, wait for first blink of all LEDs (indicates network setup),
   then keep button for 3 following blinks and release it.
3. Open 192.168.1.1 address in your browser and upload sysupgrade image.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

1 files changed, 126 insertions, 0 deletions

diff --git a/target/linux/ath79/dts/qca9531_alfa-network_r36a.dtsi b/target/linux/ath79/dts/qca9531_alfa-network_r36a.dtsi
new file mode 100644
index 0000000000..697b20e999
--- /dev/null
+++ b/target/linux/ath79/dts/qca9531_alfa-network_r36a.dtsi
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "qca953x.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &wmac;
+	};
+
+	gpio_export: gpio-export {
+		compatible = "gpio-export";
+		#size-cells = <0>;
+
+		watchdog-enable {
+			gpio-export,name = "watchdog-enable";
+			gpio-export,output = <1>;
+			gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+		};
+	};
+
+	keys: keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			linux,code = <KEY_RESTART>;
+			gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+	};
+
+	watchdog {
+		compatible = "linux,wdt-gpio";
+		gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
+		hw_algo = "toggle";
+		hw_margin_ms = <25000>;
+		always-running;
+	};
+};
+
+&eth0 {
+	status = "okay";
+
+	phy-handle = <&swphy4>;
+};
+
+&pinmux {
+	enable_gpio4: pinmux_enable_gpio4 {
+		pinctrl-single,bits = <0x04 0x0 0xff>;
+	};
+
+	enable_gpio16: pinmux_enable_gpio16 {
+		pinctrl-single,bits = <0x10 0x0 0xff>;
+	};
+};
+
+&spi {
+	status = "okay";
+
+	num-cs = <1>;
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <50000000>;
+		m25p,fast-read;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x000000 0x060000>;
+				read-only;
+			};
+
+			partition@60000 {
+				label = "u-boot-env";
+				reg = <0x060000 0x010000>;
+			};
+
+			art: partition@70000 {
+				label = "art";
+				reg = <0x070000 0x010000>;
+				read-only;
+			};
+
+			partition@80000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x080000 0xf80000>;
+			};
+		};
+	};
+};
+
+&uart {
+	status = "okay";
+};
+
+&usb0 {
+	status = "okay";
+
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	hub_port0: port@1 {
+		reg = <1>;
+		#trigger-source-cells = <0>;
+	};
+};
+
+&usb_phy {
+	status = "okay";
+};
+
+&wmac {
+	status = "okay";
+
+	mtd-cal-data = <&art 0x1000>;
+};